As high-precision angular velocity sensors,resonant optical gyroscopes have gradually become a hot spot in the research and development of the next generation of optical gyroscope due to its unique advantages in integration,low-cost and anti-interference.Based on the analysis of the principle of the resonant optical gyroscope,the visual model of the gyro digital signal processing system is established,and the open-loop output such as the resonance curve and the synchronous demodulation curve as well as the closed-loop output under the frequency-locked feedback are sim-ulated.The simulation model is used to analyze the resonance spectrum splitting phenomenon un-der sinusoidal wave modulation.An experimental device is built to verify it.The result shows that when the modulation frequency of the sinusoidal signal in the experiment is higher than half of the full width at half maxima(FWHM),refering to 2 MHz,the resonance spectrum splitting leads to obvious distortion in the linear region of the synchronous demodulation output,which seriously deteriorates the linearity of the scale factor.Therefore,the simulation model of resonant optical gyroscope can accurately and effectively simulate the working state of the system,which has guid-ing significance in noise suppression and accuracy improvement of the system.